The present invention relates to waterbeds, and particularly to a device for fastening sheets and the like in place on a waterbed.
Waterbeds of the most common type include a sturdy base supporting a box-like frame which usually includes wooden boards lying on edge and fastened together at the four corners of the frame, as well as a flat bottom structure. This box-like frame contains and supports a fluid-holding mattress. The mattress is, essentially, a water-filled flexible bag, usually made of a sheet plastics material. Ordinarily, a heater maintains the water at a desired temperature and chemicals are used to prevent growth of algae within the mattress.
Because such waterbeds provide a great deal of comfort and in their basic form are less expensive than conventional bedding, waterbeds are increasingly popular. It is also recognized that the support provided by a waterbed is often more appropriate for a person suffering from arthritis or back ailments, and this factor also contributes to the increasing popularity of waterbeds.
A particular disadvantage of waterbeds, however, in comparison with conventional boxspring and mattress bedding, is that it is very difficult to make the sheets used on waterbeds remain neat and snug on the top of the waterbed mattress. Although the bed may be made up neatly, as soon as one rests on it the sheets begin to bunch up and come untucked from around the edges of the waterbed mattress.
This tendency for the sheets to come loose from a waterbed has been countered previously by using very large sheets with plenty of extra material to be tucked under the mattress, by providing diagonal straps on the corners of a waterbed sheet, or by providing specially designed sheets including pockets at their corners for use on waterbeds. While such devices are useful on conventional mattresses, they fail to solve efficiently the problem of sheets coming loose from waterbeds.
Particularly for top sheets, failure to stay securely tucked in place is a serious problem with waterbeds. For that reason top and bottom sheets are sometimes provided as a sewn-together combination. While this helps somewhat to solve the problem of the sheets becoming loose from the bed, it results in a bed sheet over 12 feet in length, which is very difficult to launder.
Any of the above-described sheets designed particularly for waterbeds are at least somewhat difficult to fit onto a waterbed mattress, because of the great weight of the water contained in a waterbed mattress. In order to tuck a pocket portion of a waterbed sheet around a corner of the mattress, a considerable amount of water weight must be lifted. This usually must be accomplished by a person standing bent over beside the bed, and is, at best, an awkward and difficult task. Many people, particularly those who are small in stature, find the routine task of changing the sheets of a waterbed a very difficult one.
Not only is it difficult to replace conventional waterbed sheets, but the sheets designed specifically for waterbeds are much more expensive than sheets for a conventional bed of a comparable size. This is because of the extra labor and materials involved in providing pockets or corner straps on such special sheets, in order to hold them neatly in place on the bed. Additionally, since most special waterbed sheets are sold at the place and time of sale of a new waterbed, a premium price is often charged for such waterbed sheets.
Another problem associated with special waterbed sheets is that, as a result of the high inventory costs, waterbed sheets are available in a relatively small number of colors and patterns, by comparison with the usually available selection of conventional bed sheets. It is therefore undesirably difficult to obtain special waterbed sheets which match the decor of a bedroom.
Various other devices are known which attempt to secure sheets on waterbeds by attachment to frame rails of the waterbed. U.S. Pat. Nos. 3,838,470 and 4,089,075 show two such devices, but these types of devices are not particularly well-adapted to being added to existing waterbeds. Others have attempted to solve the problem by the use of devices attached to waterbed frames to interconnect with buttonholes on yet other special sheets, as shown in McKneelen U.S. Pat. No. 4,486,909. Gilreath U.S. Pat. No. 4,040,133 discloses a strap of plastic film having one end held under the mattress of a waterbed by the weight of the mattress for holding special sheets, etc., equipped with hook-and-loop fasteners of the well-known type available under the trademark Velcro.
One device which performs well and is easily installed in existing waterbeds to hold ordinary flat sheets in place is disclosed in copending Hutton et al. U.S. patent application 733,701, filed May 13, 1985, now U.S. Pat. No. 4,660,240. Although this device works perfectly well, its installation requires a screw or similar fastener to pierce the liner of the waterbed frame, causing some reluctance to install the device.
What is needed, therefore, is an improved device for attaching ordinary flat sheets neatly to a waterbed, which would be inexpensive and easily installed, and whose installation would not require the liner of the waterbed frame to be punctured.